The US Centers for Disease Control and Prevention (CDC) has issued interim guidelines advocating the use of face masks and respirators by individuals during an influenza pandemic, even though the value of such protection has yet to be confirmed through rigorous research.

At a May 3 press conference, Julie Gerberding, MD, CDC director, said given that a pandemic influenza outbreak could happen at any time, the agency did not want to wait months or years for study results to provide scientific validation of face mask and respirator use.